Stop showing OUT OF STOCK size only – Not Item

WooCommerce 2.0.4

I have a shirt – Small, Med, Large

I know how to get an item to not display if OUT OF STOCK. How do I get only the ‘size attribute’ (i.e.: Small, etc.) to not display when the size is no longer available?

Thanks.

https://www.ads-software.com/extend/plugins/woocommerce/